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Can you help please Richard? I have an HP 5150 it is about 41/2 years old and has never given any problems. today, although the cartridge was getting low it was not showing empty but started printing blue colours. I changed the cartridge after first wiping the bottom with a damp cloth ( as I had been advised to do)and ink seemed to be flowing fine It did not print out a test page. I started to try to print again and although the colour started fine it changed to bluey about 1/3 way through. tried a new cartridge and the same thing happened. tried aligning cartridge and colour and suddenly it clicked in and printed a test page which looked perfect, however when I tried to print out the colour changed again. Do you think my printer has had it or is there something else I should try?